I. Field of the Invention
The present invention relates to novel nucleic acids and methods for detecting Xanthomonas campestris pathogenic to plants belonging to the family Gramineae using the same.
II. Description of the Related Art
Bacteria (all bacteria including bacteria pathogenic to plants) are conventionally identified by biochemical assays (examinations for microbiological characteristics) such as metabolizabilities of sugars and organic acids. However, these methods are not quick or simple, but laborious and time-consuming, and require skill. As a method for simply identifying bacteria, a method exploiting the differences in the nucleotide sequences of 16S ribosome RNAs is known. However, by this method, it is difficult to identify the taxonomic group below the species (such as pathovar).
As a method for simply identifying a bacterium belonging to Xanthomonas campestris, methods are known in which fatty acids or proteins constituting the bacterial cell are analyzed. However, these methods are not reproducible and it is difficult to distinguish Xanthomonas campestris pathovars pathogenic to plants belonging to the family Gramineae from nonpathogenic Xanthomonas campestris strains.
Further, to determine whether a Xanthomonas campestris strain pathogenic to plants belonging to the family Gramineae exists in natural environment such as in plants, soil or water, it is necessary to apply a sample (plant, soil, river water or the like) obtained from the natural environment on an agar medium, to incubate the agar medium to form a single colony, and to determine whether the bacteria forming the single colony are the pathogenic Xanthomonas campestris of interest or not by the above-mentioned conventional method.